Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass, Sports Turf, Golf Course Grass
Variety / Cultivar
Common blend of turf-type cultivars like 'Midnight' and 'Baron'
Hardiness Zones
USDA Zones 3 through 7, highly cold tolerant, goes into winter dormancy in colder climates.
About This Grass
Forms a lush, dense, fine-to-medium textured turf with a rich dark green to blue-green color. Mown height typically ranges from 1.5 to 2.5 inches, while unmowed growth can reach 12 to 24 inches with distinctive pyramid-shaped panicle seed heads.
Blade Characteristics
Blades are medium-fine in width (2-4mm), flat to folded with distinct parallel veins, and feature characteristic boat-shaped tips. Vernation is folded in the bud with a short, membranous ligule and no auricles.
Root System
Moderately deep fibrous root system combined with extensive rhizomes, creating a dense, tough sod. Moderate establishment speed from seed, but excellent recovery from wear due to rhizomatous spread.
Growing Information
Origin Region
Europe, Northern Asia, and parts of the mountains of North America; widely naturalized and cultivated across temperate regions worldwide.
Growth Habit
Aggressively rhizomatous, forming a dense, uniform sod and spreading through underground stems.
Sunlight & Water Needs
Requires full sun (minimum 6-8 hours daily) for optimal growth, though some cultivars offer moderate shade tolerance. High watering needs during dry spells to maintain green color, enters dormancy during severe drought.
Mowing & Maintenance
Mow at 2.0 to 3.0 inches. High maintenance requirement with regular fertilization (3-5 lbs N per 1000 sq ft annually), frequent irrigation, and periodic dethatching and core aeration.
Special Characteristics
Exceptional wear tolerance and self-repairing capabilities due to rhizomes. Good cold hardiness and winter color retention in milder climates. Susceptible to certain diseases like dollar spot, summer patch, and leaf spot.
Ecological Information
Introduced species in North America widely used for erosion control, residential lawns, and sports fields. Provides good soil stabilization and water filtration, though lower wildlife food value compared to native prairie grasses.